Method and Apparatus for Selectively Enhancing an Image

1. A method of selectively enhancing regions in an image, comprising: determining one or more bright regions in the image and one or more dark regions in the image, wherein the bright regions and the dark regions include pixels with an intensity value falling outside a desired intensity range, and wherein determining the one or more bright regions in the image having pixels with an intensity value falling outside the desired intensity range comprises: determining pixels in the image with intensity values greater than a threshold value; and determining whether the determined pixels correspond to a first light source in the image based on a size and a shape of one or more regions encompassing the determined pixels; and enhancing the one or more dark regions and the one or more bright regions in the image using a light source image having pixels with a desired intensity value, wherein enhancing the one or more dark regions and the one or more bright regions in the image using the light source image having pixels with the desired intensity value comprises replacing the pixels in at least one dark region and at least one bright region of the image with the pixels of the light source image by superimposing the light source image onto the at least one dark region and the at least one bright region in the image.

2. The method of claim 1 , further comprising generating the light source image for brightening one or more dark regions in the image.

3. The method of claim 2 , wherein generating the light source image for brightening the dark regions in the image comprises: modeling a light source of the desired intensity value for brightening the dark regions in the image; and generating the light source image using the modeled light source.

4. The method of claim 3 , wherein determining the one or more dark regions in the image having pixels with the intensity value falling outside the desired intensity range comprises: (a) determining at least one pixel having a lowest intensity value from the pixels in the image; (b) computing a first mean value of the pixels in the image based on the lowest intensity value of the at least one pixel; (c) determining whether the first mean value of the pixels in the image is less than a threshold value; after the steps (a) to (c), and in response to determining the first mean value of the pixels in the image is less than the threshold value, performing the following steps: (d) dividing the image into a plurality of regions; (e) computing a second mean value of pixels in each of the plurality of regions; (f) determining a minimum mean value of pixels corresponding to at least one of the plurality of regions from the second mean values of the plurality of regions; (g) determining whether the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the threshold value; (h) identifying said at least one of the plurality of regions in the image as the dark region if the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the threshold value, wherein enhancing the one or more regions in the image comprises enhancing the identified dark region; and (i) repeating the steps (a) to (h) until all the dark regions in the image are enhanced.

5. The method of claim 1 , further comprising generating the light source image for softening bright regions in the image.

6. The method of claim 5 , wherein generating the light source image for softening the bright regions in the image comprises: modeling a light source for softening one or more bright regions in the image; and generating the light source image using the modeled light source.

7. The method of claim 1 , further comprising converting the image in a desired image model.

8. The method of claim 7 , wherein the desired image model is selected from the group consisting of a grayscale image model, an RGB image model, a HSI image model, a CMY image model, a YIQ image model, and a YUV image model.

9. An apparatus comprising: a processor; and a memory coupled to the processor, wherein the memory comprises an image enhancement module stored in the form of instructions that, when executed the processor, cause the processor to: determine one or more bright regions in an image, and one or more dark regions in the image, wherein the bright regions and the dark regions include pixels with an intensity value falling outside a desired intensity range, and wherein determining the one or more bright regions in the image having pixels with an intensity value falling outside the desired intensity range comprises: determining pixels in the image with intensity values greater than a threshold value; and determining whether the determined pixels correspond to a first light source in the image based on a size and a shape of one or more regions encompassing the determined pixels; and enhance the one or more dark regions and the one or more bright regions in the image using a light source image having pixels with a desired intensity value, wherein in enhancing the one or more dark regions and the one or more bright regions in the image using the light source image having pixels with the desired intensity value, the image enhancement module causes the processor to replace the pixels in at least one dark region and at least one bright region of the image with the pixels of the light source image, by superimposing the light source image onto the at least one dark region and the at least one bright region in the image.

10. The apparatus of claim 9 , wherein the image enhancement module causes the processor to generate the light source image for brightening one or more dark regions in the image.

11. The apparatus of claim 10 , wherein in determining the one or more dark regions in the image having pixels with intensity value falling outside the desired intensity range, the image enhancement module causes the processor to: (a) determine at least one pixel having a lowest intensity value from the pixels in the image; (b) compute a first mean value of the pixels in the image based on the lowest intensity value of the at least one pixel; (c) determine whether the first mean value of the pixels in the image is less than a threshold value; after the steps (a) to (c), and in response to determining the first mean value of the pixels in the image is less than the threshold value, perform the following steps: (d) divide the image into a plurality of regions; (e) compute a second mean value of pixels in each of the plurality of regions; (f) determine a minimum mean value of pixels corresponding to at least one of the plurality of regions from the second mean values of the plurality of regions; (g) determine whether the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the threshold value; (h) identify said at least one of the plurality of regions in the image as the dark region if the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the threshold value, wherein the processor is configured to enhance the one or more regions in the image by enhancing the identified dark region; and (i) repeat the steps (a) to (h) until all the dark regions in the image are enhanced.

12. The apparatus of claim 9 , wherein the image enhancement module cause the processor to generate the light source image for softening bright regions in the image.

13. The apparatus of claim 9 , wherein the image enhancement module cause the processor to convert the image in a desired image model.

14. The apparatus of claim 13 , wherein the desired image model is selected from the group consisting of a grayscale image model, an RGB image model, a HSI image model, a CMY image model, a YIQ image model, and a YUV image model.

15. A non-transitory computer readable storage medium having executable instructions stored therein, that when executed by the processor, cause the processor to perform operations comprising: determining one or more bright regions in an image and one or more dark regions in the image, wherein the bright regions and the dark regions include pixels with an intensity value falling outside a desired intensity range, wherein determining the one or more bright regions in the image having pixels with an intensity value falling outside the desired intensity range comprises: determining pixels in the image with intensity values greater than a threshold value; and determining whether the determined pixels correspond to a first light source in the image based on a size and a shape of one or more regions encompassing the determined pixels; and enhancing the one or more dark regions and the one or more bright regions in the image using a light source image having pixels with a desired intensity value, wherein in enhancing the one or more dark regions and the one or more bright regions in the image using the light source image having pixels with the desired intensity value, the operations further comprise replacing the pixels in at least one dark region and at least one bright region of the image with the pixels of the light source image by superimposing the light source image onto the at least one dark region and the at least one bright region in the image.

16. The storage medium of claim 15 , wherein the operations further comprise generating the light source image for brightening one or more dark regions in the image.

17. The storage medium of claim 16 , wherein in determining the one or more dark regions in the image having pixels with intensity value falling outside the desired intensity range, the operations further comprise: (a) determining at least one pixel having a lowest intensity value from the pixels in the image; (b) computing a first mean value of the pixels in the image based on the lowest intensity value of the at least one pixel; (c) determining whether the first mean value of the pixels in the image is less than a first threshold value; after the steps (a) to (c), and in response to determining the first mean value of the pixels in the image is less than the threshold value, performing the following steps: (d) dividing the image into a plurality of regions; (e) computing a second mean value of pixels in each of the plurality of regions; (f) determining a minimum mean value of pixels corresponding to at least one of the plurality of regions from the second mean values of the plurality of regions; (g) determining whether the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the first threshold value; (h) identifying said at least one of the plurality of regions in the image as the dark region if the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the first threshold value, wherein enhancing the one or more regions in the image comprises enhancing the identified dark region; and (i) repeating the steps (a) to (h) until all the dark regions in the image are enhanced.

18. The storage medium of claim 15 , wherein the operations further comprise generating the light source image for softening bright regions in the image.

19. A method of selectively enhancing regions in an image, comprising: determining one or more regions in the image having pixels with an intensity value falling outside a desired intensity range; and enhancing the one or more regions in the image using a light source image having pixels with a desired intensity value; generating the light source image for brightening one or more dark regions in the image, wherein generating the light source image comprises: modeling a light source of the desired intensity value for brightening the dark regions in the image; and generating the light source image using the modeled light source; wherein determining the one or more regions in the image having pixels with the intensity value falling outside the desired intensity range comprises: (a) determining at least one pixel having a lowest intensity value from the pixels in the image; (b) computing a first mean value of the pixels in the image based on the lowest intensity value of the at least one pixel; (c) determining whether the first mean value of the pixels in the image is less than a threshold value; after the steps (a) to (c), and in response to determining the first mean value of the pixels in the image is less than the threshold value, performing the following steps: (d) dividing the image into a plurality of regions; (e) computing a second mean value of pixels in each of the plurality of regions; (f) determining a minimum mean value of pixels corresponding to at least one of the plurality of regions from the second mean values of the plurality of regions; (g) determining whether the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the threshold value; (h) identifying said at least one of the plurality of regions in the image as a dark region if the minimum mean value of the pixels corresponding to said at least one of the plurality of regions is less than the threshold value, wherein enhancing the one or more regions in the image comprises enhancing the identified dark region; and (i) repeating steps (a) to (h) until all the dark regions in the image are enhanced.